I accidentally ctrl-c'd a pegasus-submitdir archive and it won't restart. Please can you make it more robust against this?

Cheers,
Duncan.

[dbrown@sugar-dev2 ~]$ pegasus-submitdir archive /usr1/dbrown/pycbc-tmp.XSSwnpbFH2/work
^CTraceback (most recent call last):
File "/usr/bin/pegasus-submitdir", line 19, in <module>
main()
File "/usr/lib64/python2.6/site-packages/Pegasus/submitdir.py", line 506, in main
SubmitDirCommand().main()
File "/usr/lib64/python2.6/site-packages/Pegasus/command.py", line 105, in main
cmd.main(args)
File "/usr/lib64/python2.6/site-packages/Pegasus/command.py", line 48, in main
self.run()
File "/usr/lib64/python2.6/site-packages/Pegasus/submitdir.py", line 443, in run
SubmitDir(self.args[0]).archive()
File "/usr/lib64/python2.6/site-packages/Pegasus/submitdir.py", line 183, in archive
tar.add(name=path, arcname=name)
File "/usr/lib64/python2.6/tarfile.py", line 1980, in add
self.addfile(tarinfo, f)
File "/usr/lib64/python2.6/tarfile.py", line 2009, in addfile
copyfileobj(fileobj, self.fileobj, tarinfo.size)
File "/usr/lib64/python2.6/tarfile.py", line 281, in copyfileobj
dst.write(buf)
File "/usr/lib64/python2.6/gzip.py", line 197, in write
self.fileobj.write( self.compress.compress(data) )
KeyboardInterrupt
[dbrown@sugar-dev2 ~]$ pegasus-submitdir archive /usr1/dbrown/pycbc-tmp.XSSwnpbFH2/work
Submit dir already archived